Prédation préférentielle des adultes de Phytoseiulus persimilis sur certains stades de développement de la proie dans une population de Tetranychus urticae.

In order to determine the stage of Tetranychus urticae preferentially eaten by Phytoseiulus persimilis, adult predators were placed in prey colonies formed on bean leaves. The age structure of each prey colony had been previously recorded. The behaviour of the predators was then followed and the first and second prey stages eaten by the predator were noted. In these conditions, the first stage eaten by the adult female predator was preferentially a female, while no significant selective predacious behaviour was noted at the second food intake. On the contrary, prey females were less eaten than expected by a random choice by male predators which preferred eggs. Besides, it seems that the prey selection behaviour may involve kairomones.